agi.foundation.numericalmethods

(agi.foundation.segmentpropagation-2024r1.jar)

Class DelegateBasedVariable<T extends SegmentConfiguration>

java.lang.Object

agi.foundation.infrastructure.DefinitionalObject

agi.foundation.numericalmethods.SegmentPropagatorVariable

agi.foundation.numericalmethods.DelegateBasedVariable<T>

Type Parameters:

T - The segment configuration that matches the SegmentDefinition being propagated.

All Implemented Interfaces:

ICloneWithContext, IEnumerateDependencies, IEquatableDefinition, IFreezable

public class DelegateBasedVariable<T extends SegmentConfiguration>
extends SegmentPropagatorVariable

A SegmentPropagatorVariable that uses a delegate to get and set the relevant values in a segment's configuration.

Constructor Summary

Constructors

Modifier	Constructor and Description
	DelegateBasedVariable() Initializes a new instance.
protected	DelegateBasedVariable(DelegateBasedVariable<T> existingInstance, CopyContext context) Initializes a new instance as a copy of an existing instance.
	DelegateBasedVariable(double maximumStep, double perturbation, SegmentDefinition segment, SetVariableCallback<T> setter) Initializes a new instance.
	DelegateBasedVariable(double maximumStep, double perturbation, SegmentDefinition segment, SetVariableCallback<T> setter, SolverVariableScaling scaling) Initializes a new instance.

Method Summary

Modifier and Type	Method and Description
protected boolean	checkForSameDefinition(DelegateBasedVariable<T> other) Checks to determine if another instance has the same definition as this instance and returns true if it does.
protected boolean	checkForSameDefinition(SegmentPropagatorVariable other) Checks to determine if another instance has the same definition as this instance and returns true if it does.
Object	clone(CopyContext context) Clones this object using the specified context.
protected int	computeCurrentDefinitionHashCode() Computes a hash code based on the current properties of this object.
void	enumerateDependencies(DependencyEnumerator enumerator) Enumerates the dependencies of this object by calling DependencyEnumerator#enumerate(T) for each object that this object directly depends upon.
SegmentPropagatorVariableEvaluator	getEvaluator(EvaluatorGroup group) Gets a SegmentPropagatorVariableEvaluator for this variable.
SetVariableCallback<T>	getSetter() Gets the delegate that will alter the relevant value in the segment's configuration.
void	setSetter(SetVariableCallback<T> value) Sets the delegate that will alter the relevant value in the segment's configuration.
protected void	validateProperties() Validates that required properties are configured correctly in order to get an evaluator for this instance.

Methods inherited from class agi.foundation.numericalmethods.SegmentPropagatorVariable

checkForSameDefinition, freezeAggregatedObjects, getName, getPerturbationValue, getSegment, getSettings, setName, setPerturbationValue, setSegment, setSettings

Methods inherited from class agi.foundation.infrastructure.DefinitionalObject

areSameDefinition, areSameDefinition, areSameDefinition, areSameDefinition, areSameDefinition, collectionItemsAreSameDefinition, collectionItemsAreSameDefinition, collectionItemsAreSameDefinition, dictionaryItemsAreSameDefinition, freeze, getCollectionHashCode, getCollectionHashCode, getCollectionHashCode, getDefinitionHashCode, getDefinitionHashCode, getDefinitionHashCode, getDefinitionHashCode, getDefinitionHashCode, getDefinitionHashCode, getDictionaryHashCode, getIsFrozen, isSameDefinition, throwIfFrozen

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

DelegateBasedVariable

public DelegateBasedVariable()

Initializes a new instance.

Before DelegateBasedVariable.getEvaluator(agi.foundation.EvaluatorGroup) can be called, Setter (get / set), PerturbationValue (get / set) and Segment (get / set) must be configured, and Settings (get / set) must be configured with a valid MaximumStep (get / set). Scaling (get / set) defaults to NoScalingOnVariable.

DelegateBasedVariable

public DelegateBasedVariable(double maximumStep,
                             double perturbation,
                             SegmentDefinition segment,
                             SetVariableCallback<T> setter,
                             SolverVariableScaling scaling)

Initializes a new instance.

Parameters:

maximumStep - The maximum step that this variable should take.

perturbation - The perturbation that should be used when finding the function's derivative with respect to this variable.

segment - The segment that this variable will operate on.

setter - The delegate that will update the relevant value in the segments configuration.

scaling - The type of scaling to be used on this variable.

DelegateBasedVariable

public DelegateBasedVariable(double maximumStep,
                             double perturbation,
                             SegmentDefinition segment,
                             SetVariableCallback<T> setter)

Initializes a new instance.

Parameters:

maximumStep - The maximum step that this variable should take.

perturbation - The perturbation that should be used when finding the function's derivative with respect to this variable.

segment - The segment that this variable will operate on.

setter - The delegate that will update the relevant value in the segments configuration.

DelegateBasedVariable

protected DelegateBasedVariable(@Nonnull
                                DelegateBasedVariable<T> existingInstance,
                                @Nonnull
                                CopyContext context)

Initializes a new instance as a copy of an existing instance.

See ICloneWithContext.clone(CopyContext) for more information about how to implement this constructor in a derived class.

Parameters:

existingInstance - The existing instance to copy.

context - A CopyContext that controls the depth of the copy.

Throws:

ArgumentNullException - Thrown when existingInstance or context is null.

Method Detail

clone

public Object clone(CopyContext context)

Clones this object using the specified context.

This method should be implemented to call a copy constructor on the class of the object being cloned. The copy constructor should take the CopyContext as a parameter in addition to the existing instance to copy. The copy constructor should first call CopyContext.addObjectMapping(T, T) to identify the newly constructed instance as a copy of the existing instance. It should then copy all fields, using CopyContext.updateReference(T) to copy any reference fields.

A typical implementation of ICloneWithContext:

public static class MyClass implements ICloneWithContext {
    public MyClass(MyClass existingInstance, CopyContext context) {
        context.addObjectMapping(existingInstance, this);
        someReference = context.updateReference(existingInstance.someReference);
    }

    @Override
    public final Object clone(CopyContext context) {
        return new MyClass(this, context);
    }

    private Object someReference;
}

In general, all fields that are reference types should be copied with a call to CopyContext.updateReference(T). There are a couple of exceptions:

1. Fields that are aggregate parts of the object should always be copied. A referenced object is an aggregate if properties or methods on the object being copied can modify the externally-visible value of the referenced object.
2. If the semantics of the referenced object require that it have a single parent, owner, context, etc., and the object being copied is that parent, owner, or context, then the referenced object should always be copied.

If one of these exceptions applies, the CopyContext should be given an opportunity to update the reference before the reference is copied explicitly. Use CopyContext.updateReference(T) to update the reference. If CopyContext.updateReference(T) returns the original object, indicating that the context does not have a replacement registered, then copy the object manually by invoking a Clone method, a copy constructor, or by manually constructing a new instance and copying the values.

alwaysCopy = context.updateReference(existingInstance.alwaysCopy);
if (existingInstance.alwaysCopy != null && alwaysCopy == existingInstance.alwaysCopy) {
    alwaysCopy = (AlwaysCopy) existingInstance.alwaysCopy.clone(context);
}

If you are implementing an evaluator (a class that implements IEvaluator), the IEvaluator.updateEvaluatorReferences(agi.foundation.infrastructure.CopyContext) method shares some responsibilities with the copy context constructor. Code duplication can be avoided by doing the following:

1. For references to other evaluators ONLY, simply assign the reference in the constructor instead of calling CopyContext.updateReference(T). You should still call CopyContext.updateReference(T) on any references to non-evaluators.
2. Call IEvaluator.updateEvaluatorReferences(agi.foundation.infrastructure.CopyContext) as the last line in the constructor and pass it the same CopyContext passed to the constructor.
3. Implement IEvaluator.updateEvaluatorReferences(agi.foundation.infrastructure.CopyContext) as normal. See the reference documentation for IEvaluator.updateEvaluatorReferences(agi.foundation.infrastructure.CopyContext) for more information on implementing that method.

public MyClass(MyClass existingInstance, CopyContext context) {
    super(existingInstance, context);
    someReference = context.updateReference(existingInstance.someReference);
    evaluatorReference = existingInstance.evaluatorReference;
    updateEvaluatorReferences(context);
}

@Override
public void updateEvaluatorReferences(CopyContext context) {
    evaluatorReference = context.updateReference(evaluatorReference);
}

@Override
public Object clone(CopyContext context) {
    return new MyClass(this, context);
}

private Object someReference;
private IEvaluator evaluatorReference;

Specified by:

clone in interface ICloneWithContext

Specified by:

clone in class DefinitionalObject

Parameters:

context - The context to use to perform the copy.

Returns:

A new instance which is a copy of this object.

checkForSameDefinition

protected final boolean checkForSameDefinition(SegmentPropagatorVariable other)

Checks to determine if another instance has the same definition as this instance and returns true if it does. Derived classes MUST override this method and check all new fields introduced by the derived class for definitional equivalence. It is NOT necessary to check base class fields because the base class will already have done that. When overriding this method, you should NOT call the base implementation because it will return false for all derived-class instances. Derived classes should check the type of other to preserve the symmetric nature of IEquatableDefinition.isSameDefinition(java.lang.Object).

Specified by:

checkForSameDefinition in class SegmentPropagatorVariable

Parameters:

other - The other instance to compare to this one.

Returns:

true if the two objects are defined equivalently; otherwise false.

checkForSameDefinition

protected boolean checkForSameDefinition(DelegateBasedVariable<T> other)

Checks to determine if another instance has the same definition as this instance and returns true if it does. Derived classes MUST override this method and check all new fields introduced by the derived class for definitional equivalence. It is NOT necessary to check base class fields because the base class will already have done that. When overriding this method, you should NOT call the base implementation because it will return false for all derived-class instances. Derived classes should check the type of other to preserve the symmetric nature of IEquatableDefinition.isSameDefinition(java.lang.Object).

Parameters:

other - The other instance to compare to this one.

Returns:

true if the two objects are defined equivalently; otherwise false.

computeCurrentDefinitionHashCode

protected int computeCurrentDefinitionHashCode()

Computes a hash code based on the current properties of this object. Derived classes MUST override this method and compute a hash code that combines: a unique hash code seed, the base implementation result, and the hash codes of all new fields introduced by the derived class which are used in the DelegateBasedVariable.checkForSameDefinition(agi.foundation.numericalmethods.SegmentPropagatorVariable) method.

Overrides:

computeCurrentDefinitionHashCode in class SegmentPropagatorVariable

Returns:

The computed hash code.

enumerateDependencies

public void enumerateDependencies(DependencyEnumerator enumerator)

Enumerates the dependencies of this object by calling DependencyEnumerator#enumerate(T) for each object that this object directly depends upon. Derived classes which contain additional dependencies MUST override this method, call the base implementation, and enumerate dependencies introduced by the derived class.

Specified by:

enumerateDependencies in interface IEnumerateDependencies

Overrides:

enumerateDependencies in class SegmentPropagatorVariable

Parameters:

enumerator - The enumerator that is informed of the dependencies of this object.

getEvaluator

public SegmentPropagatorVariableEvaluator getEvaluator(EvaluatorGroup group)

Gets a SegmentPropagatorVariableEvaluator for this variable.

Specified by:

getEvaluator in class SegmentPropagatorVariable

Parameters:

group - The EvaluatorGroup to use to create any necessary evaluators for this variable.

Returns:

The fully configured variable evaluator.

Throws:

PropertyInvalidException - Thrown when Segment (get / set) is null, or Scaling (get / set) is null, or MaximumStep (get / set) is not greater than zero, or VariableTolerance (get / set) is negative, or Setter (get / set) is null.

validateProperties

protected void validateProperties()

Validates that required properties are configured correctly in order to get an evaluator for this instance. Derived classes should call this method when implementing DelegateBasedVariable.getEvaluator(agi.foundation.EvaluatorGroup), as well as validate their own properties.

Overrides:

validateProperties in class SegmentPropagatorVariable

Throws:

PropertyInvalidException - Thrown when Setter (get / set) is null.

PropertyInvalidException - Thrown when Settings (get / set) is null, or Segment (get / set) is null, or Scaling (get / set) is null, or MaximumStep (get / set) is not greater than zero, or VariableTolerance (get / set) is negative.

getSetter

public final SetVariableCallback<T> getSetter()

Gets the delegate that will alter the relevant value in the segment's configuration.

The setter function should have no state. A setter function typically will add the input value from the MultivariableFunctionSolver to a value in the configuration. The value in the configuration before this addition represents the initial value of this variable. Each time the solver iterates the configuration is reset to its initial configuration.

setSetter

public final void setSetter(SetVariableCallback<T> value)

Sets the delegate that will alter the relevant value in the segment's configuration.

The setter function should have no state. A setter function typically will add the input value from the MultivariableFunctionSolver to a value in the configuration. The value in the configuration before this addition represents the initial value of this variable. Each time the solver iterates the configuration is reset to its initial configuration.